1. Field of the Invention
The present invention relates to an apparatus for controlling the driving of a power window system in which the door glass of a vehicle is raised and lowered by the driving power of a motor. The auto switch is a switch for automatic operation (hereinafter reffered to as "auto switch").
2. Description of the Related Art
At a location near the driver's seat, there are provided manual switches and an auto switch as switches for the power window system.
When the driver manipulates the auto switch to bring the contacts for the raising operation or the contacts for the lowering operation into the ON state, the drive of the motor is continued until the door grass is completely closed or completely opened even after the driver releases the auto switch. When the door glass is completely closed, the movement of the door glass is prevented by the window frame or the like, whereby the drive current of the motor increases. The drive of the motor is stopped when the drive current exceeds a predetermined level.
By the way, it has been considered to detect an abnormal current due to the existence of a foreign object or substance on the locus of the upward movement of the door glass so as to stop or reverse the motor. In some systems, there is provided a full-closure detecting switch for detecting the state of the door glass approaching its full closure position so as to discriminate a current increase due to the foreign object of substance of a current increase due to the full closure of the door glass.
However, the detected drive current of the motor also becomes abnormal due to vibrations and noises so that the variation amount of the drive current exceeds a predetermined level. The vibrations are generated, for example, when the vehicle runs on a bumpy road, when the wheels of the vehicle fall into a depression on the road, or when a door is violently closed. Noise is generated, for example, when the engine is started.
Therefore, there has been a problem that noise is erroneously recognized as the presence of a foreign object or substance, even though the squeeze of the alien substance does not actually exist, and the motor is stopped or reversed.